Abolitionists, in U.S. history, especially from 1830 to 1860, advocates of the compulsory emancipation of African-American slaves. Abolitionists are to be distinguished from free-soilers, who opposed the extension of SLAVERY. The active campaign had its mainspring in the revival (1820s) in the North of evangelical religion, with its moral urgency to end sinful practices. It reached crusading stage in the 1830s, led by Theodore D. Weld, the brothers Arthur and Lewis Tappan, and William Lloyd GARRISON. The American Anti-Slavery Society, established in 1833, flooded the slave states with abolitionist literature and lobbied in Washington, D.C. Writers like J.G. WHITTIER and orators such as Wendell PHILLIPS lent strength to the cause. Despite unanimity on their goal, abolitionists were divided over the method of achieving it, Garrison advocating moral suasion, others direct political action. Uncle Tom's Cabin, by Harriet B. STOWE, became an effective piece of abolitionist propaganda, and the KANSAS question aroused both North and South. The culminating act of abolitionism was John BROWN's raid on Harpers Ferry. Abolitionist demands for immediate freeing of the slaves after the outbreak of the CIVIL WAR resulted in Pres. Lincoln's Emancipation Proclamation. The abolitionist movement was one of high moral purpose and courage; its uncompromising temper hastened the demise of slavery in the U.S.